China told banks to stop loans for third-home purchases as the government steps up measures to cool property prices with some of the “most draconian” orders yet. Shares of developers and banks tumbled.

Banks should also suspend lending to buyers who can’t provide tax returns or proof of social security contributions, the State Council said in a April 17 statement. The latest measures come on top of orders to banks this year to set aside more deposits as reserves and raise mortgage rates, and steps to re-impose a sales tax on homes.

“These are the most draconian measures on the property market in history,” Jun Ma, Deutsche Bank AG’s Greater China chief economist, said in a note to clients today. Chinese press reports point to “panic selling” by investors who own more than one home in Shanghai, Beijing and Shenzhen, he said.